Rotary grass trimmers employing flexible lines for accomplishing the cutting operation, rather than a steel blade, have become increasingly popular. The use of flexible line provides a much safer apparatus than does the use of a steel blade. Then, as a resulting advantage, the use of flexible line permitted the development of grass trimmers which were of lighter weight and therefore more easily manageable than, and used somewhat less power than, the trimmers which had steel blades.
The intrinsic advantages of the hand-held, flexible line trimmer have enabled users to operate this type of trimmer for a broad range of purposes, many more uses than had been generally considered with the heavier steel blade variety. People began to use this lighter weight, safer trimmer for multiple purposes: trimming grass along house foundations; trimming along fence lines; trimming, in what is commonly described as an "edging" operation, along a concrete sidewalk; and, even, while they have the trimmer available, utilizing the trimmer to mow small areas of grass.
However, as has already been recognized in the art, the use of the hand-held grass trimmer for multiple purposes is best accomplished by the use of some form of support frame attached to the grass trimmer. A wheeled support frame was found necessary for some purposes because the hand-held grass trimmer, simply held in the air above the area being trimmed, would cause uneven trimming and would be tiring to the user.
I have found in the prior art a number of patents for attachments and adaptations for the flexible line trimmer. These are shown in the following patents:
______________________________________ U.S. Pat. No. 4,077,191 Pittinger, Sr. et al March 7, 1978 U.S. Pat. No. 4,182,100 Letter Jan. 8, 1980 U.S. Pat. No. 4,205,439 Sweet June 3, 1980 U.S. Pat. No. 4,224,784 Hansen et al Sept. 30, 1980 U.S. Pat. No. 4,531,350 Huthmacher July 30, 1985 G.B. 1,551,622 Dawson Aug. 30, 1979 ______________________________________